The present invention relates to decorative laminating papers and to decorative laminates incorporating those papers. More particularly, the invention relates to decorative laminating papers in which the decor sheet or the overlay sheet contains paper chips of one or more colors, to impart a randomly distributed colored pattern to the sheet.
High-pressure decorative laminates are laminated articles comprising plural layers of synthetic resin impregnated paper sheets consolidated or bonded together into a unitary structure under high heat and pressure. Conventionally, the decorative or print layer is a sheet of high quality cellulose fiber and fillers. The decorative sheet may be overlaid with a low basis weight transparent sheet, known as an overlay. These sheets are impregnated with a thermosetting resin such as melamine formaldehyde, assembled with a plurality of core or body sheets of a fibrous cellulosic material, usually unbleached kraft paper, impregnated with a thermosetting resin such as phenolformaldehyde resin, and cured. Typically, up to seven or eight core sheets are consolidated with a decor sheet and an overlay sheet to form a decorative laminate. However, in the low pressure process, a single decor sheet is directly laminated onto a core sheet, typically chip board.
Decorative laminates are widely employed in the building industry for use as counter tops, kitchen and bathroom work surfaces, wall paneling, flooring, cabinetry, partitions and doors. Because they are generally more durable than wood and provide an attractive appearance, decorative laminates are also popular in the furniture industry, primarily as tops for furniture such as tables and desks. Their low cost, impact and abrasion resistance, durability, clarity, and their resistance to heat, ultraviolet light and mild chemicals make decorative laminates very useful.
In the preparation of solid color decorative papers, the colorant or pigment is typically added to the pulp prior when forming the sheet on the papermaking machine. This method generally has been limited to producing decorative papers which have a uniformly solid color. Until recently, if a decorative design, pattern or a kaleidoscope effect were desired in a decorative sheet, a separate printing process with a printing cylinder or plate specifically made for each color and intensity was required. U.S. Pat. No. 5,252,378 discloses a method of producing decorative sheets having localized patterns of color, wherein the color is incorporated into the fibers of the decorative sheets as various wax-encapsulated pigments or beads, containing numerous individual pigment particles of one or more colors.
The incorporation of plastic chips, foil chips, pigmented resin particles, metallic flakes, etc., into decorating materials such as plastic decorative surfaces, vinyl floorings, etc., is known in the art. U.S. Pat. No. 4,699,820 and U.S. Pat. No. 4,605,584 disclose decorative materials comprising crinkled chips of platelet materials or metallic flakes. U.S. Pat. No. 4,126,727 discloses a flooring structure in which pearlescent chips or flakes are placed over an alternating light and dark background pattern.
It would be desirable to have a decorative laminating paper for use in decorative laminates which is economical to manufacture and in which multicolored patterns are created within the sheet in a one-step process without printing the decor, i.e., interspersed among the fibers to improve its appearance of localized single or multicolored patterns characteristics. The present invention provides such a decorative sheet, a method for preparing such decorative sheet, and a decorative laminate using such decorative sheet.